The present invention relates to perennial ryegrass with a spreading growth habit. All publications cited in this application are herein incorporated by reference.
Turfgrass plays a major role in our daily life. Turfgrass, from a beautification standpoint, provides a canvas for landscaped areas contributing to aesthetic appeal and adding to economic value. Recreational facilities include an array of sports fields, golf courses, parks and lawns. Turfgrass also provides functional value including dust control, erosion control, and glare reduction.
Use and appearance are prime considerations for turfgrass. To best serve a particular function, the turf should be suitable for the use for which it is intended and aesthetically appealing. It should also be well-adapted to the environment where it will be planted. Based on climatic adaptation, turfgrass species have been placed into four categories: adapted for cool humid regions, warm humid regions, cool arid regions, and warm arid regions. The major turfgrasses adapted to the cool humid regions, and irrigated areas of the cool arid regions, are species of Agrostis, Poa, Festuca, and Lolium. In the warm humid and irrigated areas of the warm arid regions, the major adapted turfgrasses are species of Cynodon, Zoysia, Stenotaphrum, Eremochloa, Paspalum, Festuca, and Agropyron. In the non-irrigated warm arid regions, species of Buchloe and Bouteloua are adapted.
Perennial ryegrass (Lolium perenne L.), also called English ryegrass, is a cool-season perennial bunchgrass native to Europe, temperate Asia, and North Africa. It is widely distributed throughout the world, including North and South America, Europe, New Zealand, and Australia. Perennial ryegrasses can be grown on their own for lawns in the northern regions, and are widely used as a mixture with permanent grasses or in new lawn establishment. They are also popular for winter overseeding quality Bermuda lawns, golf areas and sports fields while they are dormant in Southern states. Most golf course greens today are overseeded with perennial ryegrass for winter color cover and a better playing surface.
Perennial ryegrass lawns are one of the best lower maintenance lawns of the cool season grasses. Perennial ryegrass is one of the toughest and most wearable turf covers that can be grown. Perennial ryegrass is noted for quick germination, shiny green color, fine texture and dense forming sod. High disease and insect resistance help to make perennial ryegrass one of the leading choices for lawn and athletic covers in North America.
Perennial ryegrass is also mixed with other cool season grasses to provide more density and to rejuvenate the dominant grass in the mixture. Perennial ryegrass is often added to Kentucky bluegrass to add strength and give bluegrass time to repair while the perennial is in full growth. These two grass species can be mown at the same height and retain a sod density for which both are well known. (Dunn, J. H. et al. 1997. Tall fescue, Kentucky bluegrass, and perennial ryegrass blends and mixtures. In: Turfgrass Research and Information Report. Univ. Missouri-Columbia Turfgrass Research Center.)
Perennial ryegrass is important in forage/livestock systems. High palatability and digestibility make this species highly valued for dairy and sheep forage systems. As a result, it often is the preferred forage grass in temperate regions of the world. It is a valuable winter and spring grazing crop that can be overseeded onto additional forages or used alone lengthening the pasture season. Perennial ryegrass is a fast growing multi-use forage crop requiring minimal tillage and is competitive enough to make a place for itself. Its compact growing habit reinforces the ground and gives a perfect erosion base for pastures with heavy traffic and, in the case of heavy rains or snow meltdown, it helps keep livestock out of the mud as much as possible. Perennial ryegrass is fast germinating, grows prolifically, and can be grazed heavily. Many varieties have been developed and are in “prescription” mixes or in stand-alone crops for complete pasture and hay production. The ryegrasses are well known for being companion grasses in mixes of fescue, clovers, timothy, orchard grass and many other pasture crops. The ryegrass is usually first to germinate and grow in while the others are developing. Perennial ryegrass is used to overseed many warmer season pastures that may go dormant or are growing slower due to cooler temperatures. This is one of the most diversified grasses used in the forage industry for permanent and semi-permanent pastures. (Hannaway, D. et al. 1999. Perennial ryegrass (Lolium perenne L.). Pacific Northwest Extension Publication 502.)
Among northern turfgrasses, the main species grown for sod is Kentucky bluegrass (Poa pratensis). It is attractive and widely adapted to the central United States (e.g. Midwest), where it is almost exclusively used for all manner of turf areas. It is long lived, easy to mow, and relatively easy to maintain. It is preferred by sod producers, because it produces an abundance of underground, horizontal stems (rhizomes) that hold the sod together very well at maturity at about one to one-and-one-half years, and many varieties are readily available.
Kentucky bluegrass is, however, not without certain draw backs: 1) it has a very slow germination of three weeks or longer in cool weather; 2) it is very slow to develop and seedlings are weak; 3) it is susceptible to common diseases such as smut, mildew, leaf spot, brown patch, and rusts of various types; 4) it lacks drought tolerance; 5) it is very slow to recover from disease or physical damage; 6) overseeding of old stands is very difficult and rarely successful.
Since the arrival of true turf-type perennial ryegrass varieties some 30 years ago with the varieties Manhattan and Pennfine, interest in perennial ryegrasses has significantly expanded world wide. They are not only used as seeded grasses, but even more so by sod producers and on large acreages. The newer varieties of today present several distinct advantages over Kentucky Bluegrass.
However, there are also some disadvantages to growing perennial ryegrasses. In particular, perennial ryegrass sod needs to be underlain with a very thin mono-filamentous net to hold the sod together for harvest since it does not produce sod-tying horizontal stems of any kind. The net must be cut out with every harvest and must be laid down again as the next crop is established. Remnants of the net tend to remain in the field after sod harvest and present a real problem for equipment readying the field for the next crop. These remnants tend to be picked up on axels and harrow tines, as well as wrap themselves tightly into bearings and cause the bearings to fail by over heating. In addition, perennial ryegrass is somewhat less heat and cold tolerant than Kentucky bluegrass.
The foregoing examples of the related art and limitations related therewith are intended to be illustrative and not exclusive. Other limitations of the related art will become apparent to those of skill in the art upon a reading of the specification.